The present invention relates to a composition for use in washing fabric, particularly for washing denim, prior to sale.
In the textile and clothing industries, it is desirable to wash fabrics or clothing to accomplish one or more of the following actions: bleed excess dyes, pre-shrink fabric, improve the hand of the fabric and remove sizing, a stiffening agent added to stiffen the fabric to facilitate the fabric cutting operation. To date this washing action has been done using a conventional laundry detergent. These detergents typically include one or both of non-ionic or anionic surfactants, detergent builders such as phosphates, silicates, carbonates, borates, and organic builders, which builders act to raise the pH and density of the washing solution and act as chelates, soil anti-redeposition agents such as carboxymethyl cellulose, optical brighteners, and fillers such as sodium chloride and sodium sulphate. A typical washing procedure using these detergents includes a standard 15-20 minute wash cycle, a 4 minute souring rinse to remove the alkalinity developed by the detergent, a 3 minute fresh water rinse, a 4 minute fabric softening rinse and a 3 minute water extraction cycle. Thus considerable time and energy are spent in a washing procedure. A washing composition to reduce the time and energy consumed by this washing procedure is desirable.
Attempts have been made to develop washing compositions which both clean and soften fabric in one washing cycle; see for example U.S. Pat. No. 3,704,228 issued to Eckert et al., British Pat. No. 1,329,416 issued to Samuel et al., U.S. Pat. No. 3,888,797 issued to Marumo, and U.S. Pat. No. 3,951,879 issued to Wixon.
These compositions typically include a surfactant, usually non-ionic, to achieve a cleaning effect, and an amphoteric surfactant or a quaternary salt to achieve a softening effect. These compositions need to be used in an alkaline washing solution in order to achieve a cleaning action. In an alkaline environment however, neither the amphoteric or the quaternary is thus in a form which will readily adsorb onto the fabric. For this reason these compositions fail to give sufficient softening or anti-static properties to the fabrics. Furthermore the costs of including both a non-ionic surfactant and an amphoteric surfactant or quaternary salt in these compositions increase the costs of these compositions. To the inventor's knowledge these compositions are not used in the fabric washing industry.
Another serious problem in the fabric washing art is that the washed fabric is often streaked from uneven dye removal. This problem is especially prevalent with washed denim apparel. The streaked fabric or apparel is sold as a factory sub-standard, at a significantly reduced price.